Reduction and disposal of toxic waste

Abstract

Toxic compounds, entrained in water, are dissociated in an electric arc (e.g. 12000° F.) in an airtight chamber charged with oxygen; metal ions (M + ) resulting from dissociation are recombined as gaseous oxides (MO x ) which are educted from the chamber and disposed of.

I claim: 
     
       1. A method of oxidizing toxic waste compounds entrained as a stream of toxic waste and including the steps of establishing a high temperature electric arc in the gap presented by and between the opposed ends of a pair of spaced elongated consumable electrodes located within a substantially airtight chamber, the temperature within the arc being of an intensity to dissociate the toxic compound, one of the electrodes having a longitudinal bore which opens at its gap end, feeding a mixture of oxygen and the stream of toxic waste to and through said bore so that a jet of oxygen and toxic waste is emitted at said gap where the toxic compound content is dissociated in the presence of oxygen to form gaseous oxides, and establishing via oxygen introduction sufficient pressure within said chamber to force both particulate matter resulting from electrode erosion and evolved oxide gases as a stream of effluent educted from said chamber for disposal. 
     
     
       2. A method according to claim 1 in which the toxic waste includes a chlorinated hydrocarbon and in which a reagent is fed into the electrode bore for combining with chlorine values resulting from dissociation within said chamber or in which the reagent is carried by an electrode. 
     
     
       3. A method according to claim 1 effluent stream contains particle solids derived from erosion, and including the step of subjecting the effluent stream to an electric arc gap in a second chamber to produce smaller particles. 
     
     
       4. A method according to claim 3 in which contents of the second chamber including gases educted from the first-named chamber and the smaller particles produced in the second chamber are educted and subsequently treated to settle the solids and scrubbed to remove water soluble gases. 
     
     
       5. A method according to claim 1 in which the electrode having the bore is a cathode consumed at less rate than the anode. 
     
     
       6. A method according to claim 5 in which the other electrode is an anode and including the step of adjusting the anode in relation to the arc current to maintain a stable arc as the anode is consumed. 
     
     
       7. Apparatus for oxidizing toxic waste compounds entrained in a fluid stream and converting the dissociated waste to oxides including: a substantially airtight chamber in which are positioned a pair of opposed consumable electrodes with their opposed ends spaced from one another to afford an arc gap;   means for supplying current to the electrodes to create a high temperature arc in the gap of sufficient intensity to dissociate toxic compounds;   one of said electrodes being a cathode and having a passage therethrough for a feed stream of the toxic waste compound, and means for constantly admitting oxygen under pressure into said passage along with the toxic compounds while concurrently employing an oxygen pressure sufficient to force from said chamber both gaseous oxides formed therein and entrained particles resulting from electrode erosion;   feed means respectively to advance each electrode toward the other;   a monitor for determining the position of the gap end of the cathode and for controlling the cathode feed means to position the gap end of the cathode in a substantially constant datum position as the cathode is consumed;   a sensor for sensing the flow of current to the arc gap and for controlling the feed means for the other electrode to maintain a stable arc; and means to educt said particles along with oxide gases from the chamber for disposal.   
     
     
       8. Apparatus according to claim 7 including a variable rate metering pump to deliver a stream of toxic waste to the cathode, and means to vary the rate of the pump in accordance with the arc current to prevent flooding of the arc. 
     
     
       9. Apparatus according to claim 7 in which the stream of toxic material includes a chlorinated hydrocarbon, said apparatus including means to feed a chlorine reagent into the electrode passage along with oxygen and the stream of toxic waste material, the reagent being a compound reactive with the chlorine derived from dissociation of the toxic compound. 
     
     
       10. Apparatus according to claim 7 including a second airtight chamber containing a pair of electrodes having a gap therebetween, means to communicate the two chambers so that contents in the first-named chamber resulting from dissociation including the attrition particles may be educted as effluent to the second chamber, and means to supply current to the electrodes in the second chamber to produce an arc of sufficient intensity to fracture to smaller size particulate solids educted from and introduced to the second chamber. 
     
     
       11. Apparatus according to claim 7 in which one of the electrodes carries a reagent reactive with the negative ion constituent of the toxic compound.